Hi Todd,

Thanks, but I think this solution will be the simplest, especially if I
can figure out how to get rid of the op amp.  I may have to breadboard
part of the circuit to figure it out.

Bob W.

On Thu, 2 Oct 2008 21:44:34 -0700
"Todd Bartrim" <bartrim@gmail.com> wrote:

> Hi Bob;
> About 5 years ago I went through this same issue when I began flying before
> the EM2 was available. I solved it using a 'divide by N' chip. It was a very
> basic circuit that worked pretty well, but IIRC it would sometimes become
> unstable above ~6K or 7K rpm. This wasn't much of an issue for me as I
> typically cruise at <5K. But some others with the 'C' drive would likely run
> near this point. I didn't pursue it as the EM2 was on its way (I think I
> have serial #0002).
> If you go in the archives and search for 'tach divider', you should get 16
> messages discussing it along with a couple of pics. I think I still have the
> extra chips if you want some to experiment with.
> Todd
>

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